The warming climate is having ripple effects across ecosystems, including plants, which have evolved clever mechanisms to conserve water when stressed by drought.
But are plants likelier to defend themselves against dry air or dry soil? This question is hotly debated among climate scientists, and the distinction matters: While there’s consensus on the trajectory of temperature rise over coming decades, less is known about how global warming will affect soil moisture. Understanding this dynamic may help decide the most effective ways to ensure the survival of robust plant life.
A team led by Kaighin McColl, assistant professor in the Department of Earth and Planetary Sciences and the John A. Paulson School of Engineering and Applied Sciences, have published new research in Nature Water indicating that plant drought-defense mechanisms, which involve closing tiny pores on leaves called stomata to limit photosynthesis and conserve water, are more likely triggered by dry soil than by dry air.
Their results challenge recently held views and were derived from a place with no plants at all—the barren salt flats of Utah and Nevada.
Previous research had found that plants are likelier to have closed stomata in the presence of dry air, rather than dry soils, so it was assumed that aridity triggered the drought response. But McColl and colleagues suspected these results did not tell the whole story about plant vulnerability to drier environments.
2023-11-24 11:41:03
Post from phys.org